ABSTRACT
Given its intimate relationship to the paranasal sinuses, a thorough understanding of the orbit is essential for the otorhinolaryngologist. The orbit is a quadrilateral pyramid, with its base facing forwards, laterally and slightly inferiorly. The medial wall is most relevant to otorhinolaryngologists due to the proximity of the paranasal sinuses. The roof of the orbit is formed primarily by the frontal bone. The zygomatic process of the frontal bone, the orbital surface of the zygoma and the greater wing of the sphenoid form the lateral wall. The nasolacrimal drainage system consists of the superior and inferior canaliculi which feed into the common canaliculus, lacrimal sac and subsequently the nasolacrimal duct. Dacrocystorhinostomy (DCR) is performed to relieve epiphora resulting from an obstruction of the nasolacrimal system. A thorough history and physical examination is essential to aid in identification of the site of obstruction. The initial goal is to expose the lacrimal bone and frontal process of the maxilla.
